WO2015112018A1

WO2015112018A1 - Gripper unit for gripping, picking up, transporting, and discharging boxes

Info

Publication number: WO2015112018A1
Application number: PCT/NL2015/050049
Authority: WO
Inventors: Eric WEVERS; Gerard Harmelink
Original assignee: Moba Group BV
Current assignee: Moba Group BV
Priority date: 2014-01-27
Filing date: 2015-01-26
Publication date: 2015-07-30
Anticipated expiration: 2016-07-27

Abstract

This invention relates to a gripper unit (1) and to a method which can be carried out by, for example, a robot system (500), in particular for gripping, picking up, transporting, and discharging substantially rectangular folding boxes (D) having bottom dimensions for length and width I and b, respectively, wherein the device comprises at least - a frame with controllable coupling piece (2) which connects the gripper unit with an operating arm, for example an operating arm (502, 503) of a robot, and - two substantially symmetrical oppositely arranged and operable, substantially vertical gripper plates (3a, 3b) connected with the gripper unit, for gripping and clamping the boxes on two opposite sides thereof, wherein at least on one of these sides a holder unit (10) with operable support plates is arranged, whereby at least a single support plate is placed under such a box directly after picking up of the box, and thereby takes up a substantially horizontal support position, and is moved from under the box just before the box is placed on a supporting surface, the support plate having a supporting length L, with L>0,2 I.

Description

Title: Gripper unit for gripping, picking up, transporting, and discharging boxes

The present invention relates to a gripper unit for gripping, picking up, transporting, and discharging substantially rectangular folding boxes having bottom dimensions for length and width 1 and b, respectively, wherein the device comprises at least

- a frame with a controllable couphng piece which connects the gripper unit with an operating arm, for example an operating arm of a robot, and

- two substantially symmetrical oppositely arranged and operable, substantially vertical gripper plates connected with the gripper unit, for gripping and clamping the boxes on two opposite sides thereof.

The invention further relates to a method for processing with a gripper substantially rectangular folding boxes having bottom dimensions for length and width 1 and b, respectively, comprising successively

- engaging and clamping the boxes with oppositely arranged and operable, substantially vertical gripper plates,

- picking up and thereby lifting, and then transporting the boxes to a desired position, and

- placing and discharging the boxes. The invention further comprises a robot for picking up, transporting, and discharging substantially rectangular folding boxes with a gripper unit attached to a robot arm of the robot, for instance with at least four axes.

Grippers of the above type are generally known. In JP 2002128027, such handling of boxes is described, where vertical clamping plates are utilized. Additionally, the plates are faced at their clamping sides to improve clamping.

In US8376433, the pivoting of containers about a horizontal axis is shown. Basically, a manner of grabbing and picking up is involved whereby only hooks are inserted into engaging openings intended therefor. There are no further engaging mechanisms.

In WO2005100157, a gripper for picking up egg boxes is described. As is known and clearly shown in this document, such egg boxes have a shape that closely conforms to the shape of eggs, and, more particularly, such a box can be regarded as an assembly of egg nests. These egg nests generally have the shape of a truncate pyramid, with the truncate surface as a bottom. These egg boxes are formed as a whole from cardboard or plastic. At pick-up, first an egg box is centered by two centering plates and then several carrier pins are rotated about a vertical axis to a point just under a corresponding number of nests, more particularly, the truncate surfaces thereof.

In FR2305385, a fork lift mechanism is described of which the forks can be slid sideways, i.e. perpendicular to the driving direction, underneath a load. More particularly, this is possible in both directions.

In contrast to the applications mentioned in the above-cited documents, Applicant's gripper must be able to reliably process folding boxes, more particularly so-called open top boxes. Such boxes are typically of cardboard, with a bottom comprising interlocking parts, without further lid parts. Such boxes also include boxes that, for instance after setting up, comprise pasted, taped and/or glued bottom parts. In the present case, these boxes are used as overpack boxes, i.e., in such a box, patterns of smaller packaging units are collected, such as egg boxes of the 2x3, 2x4, etc., types. The weight of such a loaded box is typically between 10 and 30 kilos. It will be clear to the skilled person that such boxes, and hence in particular the food products packaged in them, must be processed reliably and especially undamaged. This means that during pick-up, transport, and discharge of such boxes, these boxes should not be deformed, and neither should packaging units be deformed or become damaged, nor should packaging units or even separate products fall out.

Processing such packages is typically done in halls of so-called packing stations where on a relatively small floor surface a great deal of logistics must be carried out. In such a hall, not only conveyors (shunting yards of conveyor belt systems) for supply and discharge of products or half -finished products will be set up, but also product processing equipment, such as slaughtering lines, egg sorting machines, and the like.

Since such boxes will generally be processed after the earlier processing of, e.g., the food products mentioned and subsequent gathering together of the packaging units, more particularly the stacking of such boxes on pallets positioned closely together, the operating space for a typically used

manipulator or robot is limited. This means that especially picking up and discharging should not take much space.

It will be clear to the skilled person that where the above-mentioned examples of grippers are concerned, these conditions are insufficiently met. On the one hand, for the loads mentioned, such grippers provide insufficient support to the bottom constructions involved, while on the other hand only limited maneuvering space is available for additional support means. In order to remedy the above-mentioned shortcomings, the gripper

according to the invention is characterized in that at least on one of the sides mentioned, a holder unit with one or more operable support plates is arranged, whereby at least a single support plate is placed under a box directly after picking up of the box, and thereby takes up a substantially horizontal position, and is moved from under the box just before the box is placed on a supporting surface, the support plate having a supporting length L, preferably -with L > 0.2 1.

It has been found that with the gripper according to the present invention such folding boxes traversing the steps of processing, i.e., successively, engaging with the gripper plates, picking up and thereby hfting, positioning the support plates, transporting between different positions, withdrawing the support plates, placing, and finally releasing by the gripper plates and removing of the gripper, are processed highly rehably, undamaged, and operationally securely.

Thus, folding boxes with food products, more particularly folding boxes whose bottoms turn slack, for instance due to condensation, can be transported in a highly suitable manner.

According to extra advantageous elaborations of the invention, the gripper unit according to the invention has one or more of the following

characterizing features:

that the support plate comprises telescopically connected parts which can be telescopically slid out and retracted to be moved under the box and from under the box, respectively;

that the support plate is rotationally moved under the box, and from under the box;

that the support plate is moved rotationally at least about a vertical axis; that the support plate is moved rotationally at least about a horizontal axis; that such axis at picking up and at placing is moved translationally at least substantially down and up, respectively;

that for the rotational movement a pulley drive is comprised;

that for the translational movement a pulley drive is comprised; that during the translational movement an upwardly directed leverage is exerted on the support plate; and

that for the upwardly directed leverage a guide rod is comprised over which the support plate can be slid and tilted to the horizontal support position mentioned.

To reliably pick up and transport the above-mentioned boxes, the method according to the present invention is characterized in that the method further comprises in succession:

- just after the picking up and during lifting of the boxes, positioning at least a single support plate in a support position under such a box for support thereof, with supporting length L, preferably with L > 0.2 1,

- the transporting of the box,

- prior to the placing, removing the support plate, and

- finally, releasing by the gripper plates and removing of the gripper.

With great advantage, such folding boxes are transported in this manner, whereby the boxes are processed safely as well as undamaged, and also at high capacity, enabled by the combination of picking up, lifting, and supporting.

Further, the method according to the invention preferably has one or more of the following characterizing features:

that the support plate is rotationally and/or translationally moved to, and away from, its support position; and

that the support plate is moved telescopically to, and away from, its support position.

To improve the processing of the boxes, the invention also relates to a robot to which the gripper is coupled with an operation and make-up as elucidated hereinabove. Due to such a holder unit of compact size, such a robot will be suitably deploy able virtually anywhere.

According to an aspect of the invention, a robot as mentioned is

characterized by the gripper unit according to any one of claims 1-10; and it is preferably suited for carrying out the method according to any one of claims 11-13.

Below, an example of a gripper unit according to the invention and the operation thereof will be detailed and explained with reference to a drawing. In the drawing:

FIGURE 1 shows a schematic side view of a gripper unit with load,

FIGURE 2 shows a schematic view, chosen in the same direction, of a preferred exemplary embodiment of a part of such a gripper unit,

FIGURE 3 shows a side view of the gripper unit of FIGURE 2 in the support position, viewed in the direction of arrow A in FIGURE 2,

FIGURE 4 shows an isometric side view of the gripper unit of FIGURE 2 with the support plates in a retracted position; and

FIGURE 5 schematically shows an exemplary embodiment of a robot.

In the different FIGURES, the same numerals and letters refer to the same parts or indications.

The drawing shows a non-limitative example of a gripper unit for gripping, picking up, transporting, and discharging angular folding boxes (D). The gripper unit comprises a frame with controllable coupling piece 2 which connects the gripper unit with an operating arm 504 (a part of which is visible in Fig. 1), for example an operating arm 504 of a robot 500 (see Fig. 5). The unit further comprises two oppositely arranged and operable, substantially vertical gripper plates 3a, 3b for gripping and clamping between them (in a respective box engaging area) a box D as mentioned.

The gripper unit comprises a holder unit 10, with an operable support plate 11. The support plate 11 is placeable, from a release position, under a box D (at least under an engaging area as mentioned), to take up a substantially horizontal support position under a box D situated in such an area. Further, the support plate 11 is movable from this horizontal support position from under a box D, in particular just before the box is to be placed on a supporting surface. Preferably, the support plate 11 has a supporting length L, with L > 0.2 1, where 1 represents a length of a box D, measured in the same direction.

In FIGURE 1 there is shown entirely schematically a gripper unit 1 which clamps between two oppositely arranged gripper plates 3a, 3b a

substantially rectangular box D on both sides thereof. At its top, the gripper is connected with a coupling piece 2 which, in turn, may be connected with an operating arm of a robot. An example of such a robot 500, provided with a gripper unit 1, is schematically represented in FIGURE 5.

More particularly, FIGURE 1 shows, likewise entirely schematically, a holder unit 10 according to the present invention. This exemplary

embodiment involves a holder unit 10 on only one side, connected with gripper plate 3a. With a drive 100, a support plate 11 can, turning about an axis 12, be moved under the load, here box D, for support during transport thereof.

Further, two size indications are shown, that of the bottom length 1 of box D, and that of the supporting length L, i.e., that part of the support plate 11 on which the box D sits. In FIGURES 2, 3, and 4, discussed below, only the holder unit 10 is represented as part of the gripper unit 1.

In FIGURE 2 there is shown a schematic view, chosen in the same direction, of a preferred exemplary embodiment of a part of such a gripper unit, more particularly the above-mentioned holder unit 10 with drive 100.

In this preferred exemplary embodiment, the drive 100 shown is pneumatic, with a piston housing (i.e. cyhnder) 101, a piston rod 102 (of a piston cooperating with the cylinder), and two pulleys 106, 107 (a drive pulley 106 and transmission pulley 107) with first and second drive belts or toothed belts 104, 105. The piston rod 102 is connected with the first drive belt 104 by means of a belt coupling piece 103, while the second drive belt 105 is connected with the support plate by means of a support plate coupling piece 108. The above-mentioned dimensions and distances L, 1 relating to the box D are also shown.

Of the support plate 11, there are further shown a view of an edge of the plate, plate edge 11a, and a plate rib l ib on the underside of the plate. Further, a guide rod 4 secured in the holder unit is represented, over which the support plate 11 is guided and moved, from a hanging position

represented in dashed lines to the supporting position shown, in which, in normal operation, the support plate extends substantially horizontally.

Further, for the gripper plate 3a there are shown a gripper plate axis 3c and a narrow gripper plate support edge 3d.

It will be clear to the skilled person that instead of drive belts (or toothed belts) 104, 105, also transmission with chains can be applied.

In FIGURE 3, with a side view of the gripper unit of FIGURE 2 in the support position seen in the direction of arrow A in FIGURE 2, it is shown in detail that in this example the drive of the support plate 11 by

transmission pulley 107 is divided over two second drive belts 105a, 105b. It can further be seen that the guide rod 4 has guide rod parts 4a, 4b

extending on either side of two support ribs l ib.

FIGURE 4 shows, from below, an isometric side view of a corner of the gripper unit of FIGURE 2, with the support plates 11 in retracted position. In this release position, the support plate 11 is not located under a box engaging area defined by the two substantially vertical side plates 3a, 3b.

Referring especially to FIGURES 2 and 3, the operation of the device according to the invention will now be further elucidated.

For picking up a box D as mentioned above, the gripper unit 1, which is connected via coupling piece 2 to, for example, the arm of a robot, will be moved to a pick-up position, and also into a proper orientation suitable for picking up. Then, the control of the gripper unit 1 is configured such that the gripper plates 3a, 3b are clampingly applied on either side of the box D for thus lifting the box D over at least a small distance. Only if the type of box so necessitates can the box D be supported on at least a single side with just one, or also more support plates 11. To that end, right after the lifting, the support plate 11 is moved under the box D, from a (retracted) release position to a generally horizontal support position.

More particularly, the gripper plate 3a as shown here will be moved about its gripper plate axis 3c, whereby a narrow gripper plate support edge 3d supports the box D as a first support upon lifting, even before support with the support plate 11. It will be clear to the skilled person that for such support, rather than the edge 3d shown, also a few fingers or pins may be utilized. Further, a configuration without such support may be chosen, so that upon gripping and picking up, only plates clamping vertically have to be relied on.

For moving the support plate 11 (from the retracted release position) to the support position shown, the drive 100 is controlled in a manner such that the piston rod 102 in cylinder 101 is moved down whereby, via belt coupling piece 103, the first drive belt 104 is likewise moved down and thereby, via the drive pulley 106, causes the transmission pulley 107 to rotate along. In order for a small, substantially vertical movement or translation of the piston rod 102 to induce a sufficiently large movement of the support plate 11, a suitable diameter is chosen for the circumference of the tread of the second drive belt 105 on this transmission pulley 107, this drive belt 105 being connected via support plate coupling piece 108 to plate end 11c of the support plate 11, with the connection running over a freely rotating plate axis l id.

While without further measures the support plate 11 would hang down via the freely rotating plate axis 11, there is provided a guide rod 4 which supports the support plate 11 in each position thereof, namely, in the support position substantially at the plate end 11c, as is clearly represented in FIGURE 2, and in the retracted position of the support plate, in the position as represented in FIGURE 4. Upon downward movement of the support plate 11 via the described drive with pulleys 106, 107 and drive belts 104, 105, the support plate 11 is slid over these guide rod parts 4a, 4b to the support position and thereby tilted upward, these parts 4a, 4b functioning as a lever (pivot guide).

As indicated in FIGURE 2, a ratio of 2 can be chosen for the ratio of the diameters of the transmission pulley 107 and the drive pulley 106, respectively. It will be clear to the skilled person that this choice is closely connected with the distances to be bridged and the time adequate therefor. In this regard, speeds and time durations are determinative of transport times and hence of the maximum transport capacity of such a system.

Hereinabove, it has already been explained that the support plate must have a minimum supporting length L in order for slack bottoms of folding boxes to be supported reliably in operation. Particularly in cases where the boxes contain cooled, packed or non-packed, products (meat, fish, poultry), where especially the cardboard bottom of such a box will absorb moisture and will lose firmness, sound support is highly desirable. It has been found that to that end, a minimum length of 0.2 1 is very suitable, it being noted that in blanks, widths of blank parts on the short side typically extend over such a proportional length.

Also of relevance is the width B of a support plate 11 or fork. Although in this direction support is less critical, there too, suitable results are achieved with a ratio of B > 0.2 b. It will be clear to the skilled person that a control is comprised for

controlling, for instance, the manipulator or the robot with the gripper unit connected thereto. Such a control can be configured in many different ways, for instance with cameras which, through imaging, generate data which are factored into a work program, or, for instance, by incorporating a number of recipes into the software beforehand in order to execute a work program with them. In all cases, partly depending on the scope of the robot, such a work program will allow a limited number of work solutions.

Preferably, the gripper unit according to the present invention is utilized in, or in combination with, a robot 500 because the dimensions of the holder unit have been limited as much as possible, and then, on the one hand, allow the manipulation of this highly suitable support plate and, on the other hand, make use of such a robot in a small space possible. A robot 500 as mentioned is, in particular, a robot with at least four axes, for example a 4-axis robot, known per se, with a number of mutually movable robot parts 501, 502, 503, 504, in particular parts that are rotatable or pivotable relative to each other about axes XI, X2, X3, X4. In the example, the robot 500 comprises a base 501 on which a carrier 501a of a first arm 502 is arranged rotatably about a vertical axis XI. The first arm is pivotable, by a bottom end, about a horizontal pivotal axis X2 relative to the carrier 501a. A second arm 503 is coupled by a first end to a top end of the first robot arm 502 so as to be pivotable about a horizontal pivotal axis X3. A robot head or operating arm 504 (which, in this example, holds the gripper unit 1) is coupled to a second end of the robot arm 503 so as to be rotatable about a vertical axis X4. The head/operating arm 504 in this case is in itself rotatable about a horizontal axis relative to the end of the second arm 503. Obviously, the robot may also be configured in a different manner. In particular, the robot (together with a gripper coupled thereto) can be utilized for carrying out a method according to the invention.

The invention is not limited to the exemplary embodiments described. It will be clear to the skilled person that modifications in the above-described devices and method are understood to fall within the scope of protection of the appended claims.

For instance, a substantially horizontal support plate may comprise telescopically connected parts which can be telescopically slid out and retracted to be moved under the box and from under the box, respectively.

Claims

1. A gripper unit for gripping, picking up, transporting, and discharging substantially rectangular folding boxes (D) having bottom dimensions for length and width 1 and b, respectively,

wherein the device comprises at least

- a frame with a controllable couphng piece (2) which connects the gripper unit with an operating arm, for example an operating arm of a robot, and - two substantially symmetrical oppositely arranged and operable, substantially vertical gripper plates (3a, 3b) connected with the gripper unit, for gripping and clamping the boxes on two opposite sides thereof, characterized in that

at least on one of said sides a holder unit (10) with operable support plates is arranged, while at least a single support plate (11) is placed under such a box directly after picking up of the box, and thereby takes up a substantially horizontal position, and is moved from under the box just before the box is placed on a supporting surface, the support plate (11) having a supporting length L, preferably with L > 0.2 1.

2. A device according to claim 1, characterized in that

the support plate comprises telescopically connected parts which can be telescopically slid out and retracted to be moved under the box and from under the box, respectively.

3. A device according to claim 1, characterized in that

the support plate is rotationally moved under the box, and from under the box, in particular between a substantially horizontal support position and a release position.

4. A device according to claim 3, characterized in that

the support plate is moved rotationally at least about a vertical axis.

5. A device according to claim 3, characterized in that

the support plate is moved rotationally at least about a horizontal axis.

6. A device according to claim 5, characterized in that

such axis at picking up and at placing is moved translationally at least substantially down and up, respectively.

7. A device according to claim 5 or 6, characterized in that for said rotational movement a pulley drive is comprised.

8. A device according to claim 6, characterized in that

for said translational movement a pulley drive is comprised.

9. A device according to claim 8, characterized in that

during said translational movement an upwardly directed leverage is exerted on the support plate.

10. A device according to claim 9, characterized in that

for said upwardly directed leverage a guide rod is comprised over which the support plate is slid and tilted to said horizontal support position.

11. A method for processing with a gripper substantially rectangular folding boxes having bottom dimensions for length and width 1 and b, respectively, for instance using a device according to any one of the preceding claims, the method comprising successively

- engaging and clamping the boxes with oppositely arranged and operable, substantially vertical gripper plates, - picking up and thereby lifting, and then transporting the boxes to a desired position, and

- placing and discharging the boxes,

characterized in that

the method further comprises in succession

- after said picking up and lifting of the boxes, positioning at least a single support plate in a support position under such a box for support thereof, with supporting length L, preferably with L > 0.2 1,

- said transporting of said box,

- prior to said placing, removing said support plate, and

- finally, releasing by the gripper plates and removing of the gripper.

12. A method according to claim 11, characterized in that

said support plate is moved rotationally and/or translationally to, and away from, its support position.

13. A method according to claim 12, characterized in that

said support plate is moved telescopically to, and away from, its support position.

14. A robot for picking up, transporting, and discharging

substantially rectangular folding boxes with a gripper unit attached to a robot arm of the robot with at least four axes, the gripper unit comprising

- two substantially parallel oppositely arranged substantially vertical plates for clamping and lifting such a box at least over a short distance, and

- a holder unit with at least a single support plate, the support plate, just after lifting, being brought under the box for support thereof, and being moved away from under the box just before the setting down of the box.

15. A robot according to claim 14, characterized by the gripper unit according to any one of claims 1 - 10.

16. A robot according to claim 14 or 15 for carrying out the method according to any one of claims 11 - 13.